As wireless networks develop, spatial filtering creates opportunities to combat multipath fading and/or to mitigate co-channel interference at wireless devices. For example, in Heterogeneous Networks (HetNet), smart antenna arrays (e.g., switched-beam, phased array, and/or adaptive array systems) may be deployed at Access Nodes (ANs) to direct beams toward select wireless devices (or geographic areas) within a radio range of the ANs to increase signal-capturing power at the wireless devices, while suppressing and/or nullifying signals emanating to/from other wireless devices and/or ANs (i.e., “beamforming”). Smart antenna arrays are also used by wireless networks to improve long-range communications. Because ANs support a restricted number of “beam-formed” wireless devices (e.g., as a function of Sounding Reference Signal (SRS) period(s)), handover of a beam-formed (or candidate) wireless device to target ANs and/or cell sectors having high beam-form loads may result in undesirable loss of throughput and/or Quality of Service (QoS) for the beam-formed (or candidate) wireless device.
Overview
Systems and methods are described for performing handover of a wireless device to a target AN sector. For example, beam-form capable sectors of one or more target ANs may be selected from a pool of candidate sectors. At least one of the selected sectors may be prioritized (e.g., over the other sectors) based on an open beam-form seat. Handover of the wireless device from a first AN to the prioritized sector may be performed.
In another embodiment, it may be verified that a first sector offers beamforming. A list of prioritized neighboring sectors may be generated based on the verification; the neighboring sectors may be selected (e.g., for prioritization) based on an open beamforming seat. A beam-form load may be calculated for each of the prioritized neighboring sectors. The neighboring sector having a beam-form load meeting a set criteria may be selected for handover of the wireless device.
In yet another embodiment, candidate sectors may be selected from a pool of neighboring AN sectors; the candidate sectors are prioritized based on an open beam-form seat. An amount of beam-formed wireless devices may be calculated for each of the prioritized candidate sectors. The prioritized candidate sector with a least amount of beam-formed wireless devices may be selected for handover of the wireless device. Handover of the wireless device from a first sector of a first AN to the selected candidate sector may be performed.